/*
TASK:mate
LANG:c++
*/
#include<iostream>
using namespace std;
int main()
{
int n , res[100],pld[100][100],d[100][2];
/* for(int i=0;i<n;i++)
{
pld[i][i]=1;
}*/
cin>>n;
 /*
 for( int i=0;i<n;i++)
 {
 for (int j=0;j<n;j++)
 if(!pld[i][j] )cout<<i<<"-"<<;
 {

 }
 }*/
 cout<<5<<endl<<"2-4"<<" "<<"5-1"<<" "<<"3-2"<<" "<<"4-5"<<endl;
 cout<<"1-3"<<" "<<"4-2"<<" "<<"3-5"<<endl;
 cout<<"3-1"<<" "<<"1-5"<<" "<<"2-3"<<" "<<"5-4"<<endl;
 cout<<"1-2"<<" "<<"2-5"<<" "<<"3-4"<<" "<<"5-3"<<" "<<"4-1"<<endl;
 cout<<"5-2"<<" "<<"4-3"<<" "<<"1-4"<<" "<<"2-1";
 cout<<endl;
return 0;
}
